Door threshold



7 Feb. 22, 1938.

C. B. DAVIS Filed Sept. 18, 1955 2 Sheet-Sh aet 1 W mm. k i H w .i

41 J, Q P 0 g 3 Arm Z 157%? W y a 2 4 2 5 A O w 1 64 Feb. 22, 1938.

DOOR THRESHOLD Filed Sept. 18, 1935 2 Sheets-Sheet 2 Patented Feb. 22,1938 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to improvements in door thresholds. As at presentconstructed, the door is designed to fit closely to the floor for thispurpose but this results in the door, as it is opened, dragging andstriking rugs or carpets on the floor. With this in mind, it is the mainobject of my invention to provide a means for automatical- -ly sealingor closing up the space below a door as the door is closed.

Another object is to provide a device of this kind, including operatingcam blocks secured to the door frame side at the floor line and athreshold plate pivotally mounted by one edge along the bottom of thedoor and spring set to normally lay flat along the bottom of the door,the free edge of the plate being adapted to engage one of the cam blocksas the door closes and swing down against the floor and to engage theother cam block as the door opens and swing back up beneath the door.

With these and other objects in View, the iiivention resides in thenovel construction and arrangement of parts as hereinafter fully setforth and claimed, reference being had to the accompanying drawings,wherein:

Figure 1 is a fragmental elevation of a door and associated parts, thedoor being closed and provided with my invention.

Figure 2 is an enlarged section along the line 2-2 in Figure 1, showingthe threshold plate drawn upward clear of the floor as the door is aboutto be closed.

Figure 3 is a view similar to Figure 2, showing the door closed and thethreshold plate engaging the floor.

Figure 4 is an inverted plan view of the door, showing the grooves andsockets necessary in the bottom edge of the door to mount my invention.

Figure 5 is an enlarged inverted plan view partially broken out andshowing my invention mounted on the door.

Figure 6 is a fragmental vertical section through the bottom of the doorshowing the threshold plate and one of the springs.

Figure '7 is a fragmental perspective view of the lower side portion ofthe door frame showing the mounting of the cam blocks, and

Figure 8 is an enlarged, fragmentary, sectional view taken on the sameplane as Figure 6.

Referring now with more particularity to the drawings, the referencecharacter A designates a door of any conventional form hinged at B inthe frame C. Ordinarily, the bottom D of the door would be disposed orarranged to just clear the floor E so that the door could close thespace in the frame C but, as aforesaid, the door would then have atendency to drag on the floor and to drag up carpets or rugs spread onthe floor.

In accordance with my invention, the door A is cut short or hung highenough in the frame to provide a substantial clearance space 8 betweenthe door and the floor E, as shown, and my auto matic threshold deviceor assembly designated generally at 2 is arranged to close this spacewhen the door is closed. The bottom of the door is provided with agroove 3 extended from one edge to the other of the door adjacent whatis hereinafter termed the rear side i of the door, rear referring here'to the trailing side of the door as it closes. At spaced points thedoor is cut out deeper and laterally to provide spring wells or seats 5and additionally at the free edge of the door a notch 6 is cutcommunicating with the aforesaid groove 3. Preferably the groove 3 isuarter-round in section or end View as shown in Figures 2 and 3 to avoidweakening the adjacent rear or trailing side of the door as will beunderstood.

An elongated mounting plate I is mounted along the bottom of the door byscrews 8 and extends at one edge 9 partially across the groove 3 and hasa narrow rib or web I turned inwardly or upwardly into the groove nearits frontal edge as shown. The threshold plate II is also of elongatedform wider than the plate 1 and is preferably slightly arcuate in crosssection (Figures 2 and 3) so as to lay fiat over the plate I as shown. Abead or U-shaped roll I2 is formed along the rear edge of the plate H,is stiffened by a wire or rod l3 soldered in its bight and is turnedinwardly and upwardly into the groove 3 along the rear edge 9 of saidmounting plate I. The frontal edge I4 of the threshold plate ll thenoverlies the frontal edge of said mounting plate. The plate ll extendsclear across the bottom of the door and across the notch 6.

Bow leaf springs l are provided and are disposed freely in the springwells 5 in the door, each spring with one end 56 hooked over the rib illon the mounting plate and the other hooked end I! hooked over the freeedge I 8 of the roll 52. The springs l5 are tensioned to normally springtogether at their ends and, engaged as shown and described with theparts, hold the threshold plate ll tightly up against the door and withthe roll 12 held tightly against the mounting plate edge 9. Then thethreshold plate ll may be swung downward at its free edge M and as theroll l2 moves up over the edge 9 of the mounting plate 1, the springswill also act to continue this swinging movement of the plate i i.

A substantially triangular cam block it] is secured by a screw 20 to theside of the door frame C adjacent the door stop F and has one point 2!turned out from the stop at a height just nicely to enter the notch 6 inthe door A as it closes, the point thus striking above the edge I4 ofthe threshold plate H and the arcuate face 22 of the cam block guidingand swinging the plate down against the floor E, as will be apparent inFigures 2 and 3. When the free edge M of said plate ll strikes the.floor, the plate stands at an angle as shown due to its being wider thanthe height of the space I between the door and floor, and of course thisspace is now closed while the door is closed. A rounded, substantiallysemicircular or half-round cam block 23, is also secured by a screw 24to the door frame side outwardly of the aforesaid cam block i9 andspaced therefrom so that the. threshold plate ll may swing down asdescribed in the space 25 between these blocks. Now as the door isopened the plate H strikes the rounded face 2% of this cam block 23 andis raised thereby, and the springs l5 snap the plate back up against thebottom of the door opening the space i, so that the door may swingfreely open and clear the floor E by a good margin.

The above. action of the plate i l in closing and opening the spacebetween the door and floor is now to be entirely automatic and positive,and the clearance space is only closed when needed, that is, when thedoor itself is closed.

While I have herein set forth a certain preferred embodiment of myinvention, it is understood that I may vary from the same in minordetails, so as best to construct a practical device for the purposeintended, not departing from the spirit of my invention and within thescope of the appended claims.

I claim:

1. In a device of the ln'nd described for mounting upon a conventionalassembly of upright door frame and door hingedly mounted therein forhorizontal movement, there being a groove formed along the bottom edgeof the door, the groove being expanded laterally at spaced intervals toform spring seats, a mounting strip secured along the bottom edge of thedoor partially over the forward portion of the groove, an upstanding ribextending along the mounting strip and within the said groove of thedoor, a threshold strip disposable in a raised position in substantialparallelism with the mounting strip and disposable in a loweredposition, the threshold strip being formed with a U-shaped roll alongits predetermined rear edge with the bight of the roll extended into thedoor groove over the rear edge of the mounting strip and having abearing thereon, bow-springs mounted freely within the spring seats ofthe door groove. and engaging at their ends the said rib and roll of themounting and threshold strips, the spring ends in engagement with theroll being below the other spring ends when the strips are insubstantial parallelism and so disposed that the springs will be movedso that their bias is reversible, to hold the threshold strip in eitherthe raised or lowered position, means for lowering the threshold stripas the door is closed, and separate means for raising the thresholdstrip as the door is opened, the said threshold strip fulcruming uponthe rear edge of the mounting strip under the action of the saidsprings.

2. In a device of the class described for mounting upon a conventionalassembly of vertical door frame having a door hinged therein for openingand closing horizontally, the door having a groove formed along itsbottom edge, the groove being expanded laterally at spaced intervals toform spring seats, a strip-like mounting plate secured to the bottomedge of the door and partially over the forward side of the said groove,an upstanding inwardly turned rib on the mounting plate, the said ribbeing disposed within the said door groove, a strip-like threshold platehaving a U- shaped roll along its predetermined rear edge, the saidthreshold plate being disposed along under the mounting plate with thebight of the roll disposed within the door groove and having a fulcrumbearing upon the rear edge of the mounting plate at the angle formed bythe juncture of the roll with the plate, said threshold strip beingdisposable in a raised position in substantial parallelism with themounting strip and disposable in a lowered position, bow springs mountedwithin the spring seats of the door groove and engaging at their endsthe said rib of the mounting plate and the depending flange of the rollof the threshold plate, the spring ends in engagement with the. rollbeing below the other spring ends when the strips are insubstantialparallelism and so disposed that the springs will be moved so that theirbias is reversible, whereby.

the threshold plate may be snapped into either its raised or loweredposition and there held, the said door having a notch formed in itslower free corner in cooperative alignment with the threshold plate, atriangular cam block secured to the door frame at its lower end andadapted to enter said door notch as the door is closed and engage andguide the threshold plate downward, and a complemental rounded cam blocksecured to the door frame in spaced relation to the triangular block andadapted to engage the threshold plate and raise same as the door isopened.

3. A device. of the class described comprising a mounting strip, athreshold strip disposable in substantial parallelism therewith andarranged to pivot intermediate its side edges on one side edge of themounting strip, cam means to initiate operation of said threshold strip,contractile spring means engaging said mounting strip and engaging saidthreshold strip on opposite sides of the pivotal axis of the thresholdstrip, the zone of engagement of the contractile spring means with thethreshold strip when the. strips are in substantial parallelism beingbelow the zone of engagement of the contractile spring means with themounting strip, whereby the spring means will urge the strips togetherwhen in substantial parallelism and the spring means will be moved sothat the bias is reversed to urge separation of the strips when they areout of sub-stantial parallelism.

4. A device of the class described comprising a mounting strip, athreshold strip disposable in substantial parallelism therewith having araised hook-end portion engaging and fulcrumed on one side edge of themounting strip, cam means to initiate operation of the threshold strip,a bowshaped contractile spring means at opposite ends engaging themounting strip and the. free end of said hook-end portion, the zone ofengagement of the said spring means with the hook-end portion when thestrips are in substantial parallelism being below the zone of engagementof the spring means with the mounting strip, whereby the spring meanswill urge the strips together when in substantial parallelism and thespring means will be moved so that its bias is reversed to urgeseparation of the strips when they are out of substantial parallelism.

CECIL B. DAVIS.

